Lobster Thermidor - I'm Soliciting Advice Here

So my son and I are on the hook for V Day dinner tonight. We plan on making Lobster Thermidor for Mrs DonChowder and daughter. It’s kind of an old school dish that you don’t see very often so I don’t have too many ideas on how to go about it. Most of the recipes I’ve seen are using a basic béchamel for the lobster chunk mixture before it goes back into the lobster bodies. But some recipes are calling for egg yolks. Anyone here made this recently and have any advice?